Fingerprinting is inherent and unique to everyone. With the development of sciences and technologies, a variety of display devices with fingerprint recognition function, such as mobile phones, tablet computers and smart wearable devices, etc., exists on the market. In this way, before operating such display device with the fingerprint recognition function, a user only needs to touch a specific region of the display device with his finger, and authority verification can be achieved through the recognition of the fingerprint recognition unit, thereby simplifying the authority verification process. In accordance with the principle of operation, the fingerprint recognition may include light-sensitive fingerprint recognition and ultrasonic fingerprint recognition, etc.
Fingerprints consist of a series of ridges and valleys located on the skin surface of the fingertip. For light-sensitive fingerprint recognition, the intensities of the light reflected by the ridges and valleys received by the fingerprint recognition unit are different so that the current/voltage signal converted from the reflected light formed at the ridge positions and the current/voltage signal converted from the reflected light formed at the valley positions are different in magnitude, and the fingerprint recognition can then be performed based on the size of the current/voltage signals. The fingerprint recognition unit generally includes a photodiode and a storage capacitor, wherein the photodiode and the storage capacitor collectively convert the light reflected via the touch body into a current/voltage signal. However, due to the presence of ambient light (sunlight or light, etc.), the accuracy of the detection result of the fingerprint recognition is reduced.